To compare the effectiveness of prostaglandins versus amniotomy and/or oxytocin for labor induction in twin pregnancies with an unfavorable cervix, and to assess differences in induction and labor duration.

We conducted a retrospective cohort study including twin pregnancies with a Bishop score <7 undergoing labor induction at ≥34 weeks of gestation in two tertiary maternity units between 2017 and 2023. Advanced gestational age was defined as >37 weeks for monochorionic and >38 weeks for dichorionic twin pregnancies. Women receiving prostaglandins were compared with those undergoing amniotomy and/or oxytocin. The primary outcome was vaginal delivery of the first twin. Secondary outcomes included indications for cesarean delivery, severe postpartum hemorrhage, neonatal morbidity (5-minute Apgar score <7 or umbilical artery pH <7.05), total duration of induction, and time in the delivery room. A propensity score matching approach was used to account for confounding.

A total of 272 women were included (98 prostaglandins; 174 amniotomy/oxytocin). In unadjusted analyses, vaginal delivery of the first twin was less frequent in the prostaglandin group (70.4% vs. 80.5%, p = 0.03), and severe postpartum hemorrhage was more frequent (18.4% vs. 8.0%, p = 0.02), while neonatal morbidity was similar. Time in the delivery room did not differ between groups (11.35 vs. 10.50 hours, p = 0.45), while the total duration of induction was longer with prostaglandins. After propensity score matching (80 pairs), no significant differences were observed for vaginal delivery of the first twin (67.5% vs. 76.2%; OR 1.54, 95% CI 0.77–3.09), failed induction (10.0% vs. 10.0%; OR 1.00, 95% CI 0.38–2.66), severe postpartum hemorrhage, or neonatal morbidity. Time in the delivery room did not differ between groups (mean difference +0.09 hours, 95% CI −1.73 to 1.91), while the total duration of induction remained longer in the prostaglandin group.

In twin pregnancies with an unfavorable cervix, we found no significant difference between prostaglandins and amniotomy and/or oxytocin in rates of vaginal delivery or morbidity after adjustment; but prostaglandins were associated with a longer induction duration.